5 papers
XL-Calibur Polarimetry of Cyg X-1 Further Constrains the Origin of its Hard-state X-ray Emission
Hisamitsu Awaki, Matthew G. Baring, Richard Bose +36
The balloon-borne hard X-ray polarimetry mission XL-Calibur observed the Black Hole X-ray Binary (BHXRB) Cygnus X-1 (Cyg X-1) during its nearly six-day Long Duration Balloon (LDB)…
Evaluation of several explanations of the strong X-ray polarization of the black hole X-ray binary 4U 1630-47
Henric Krawczynski, Yajie Yuan, Alexander Y. Chen +6
The Imaging X-ray Polarimetry Explorer (IXPE) observations of the X-ray binary 4U 1630-47 in the high soft state revealed high linear polarization degrees (PDs) rising from 6% at 2…
Cygnus X-3 revealed as a Galactic ultraluminous X-ray source by IXPE
Alexandra Veledina, Fabio Muleri, Juri Poutanen +127
The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds the critical value, known as the Eddington limit. Discovery of ultralumi…
Dramatic Drop in the X-Ray Polarization of Swift J1727.81613 in the Soft Spectral State
JiÅÃ Svoboda, Michal DovÄiak, James F. Steiner +34
Black-hole X-ray binaries exhibit different spectral and timing properties in different accretion states. The X-ray outburst of a recently discovered and extraordinarily bright sou…
An IXPE-Led X-ray Spectro-Polarimetric Campaign on the Soft State of Cygnus X-1: X-ray Polarimetric Evidence for Strong Gravitational Lensing
James F. Steiner, Edward Nathan, Kun Hu +134
We present the first X-ray spectropolarimetric results for Cygnus X-1 in its soft state from a campaign of five IXPE observations conducted during 2023 May-June. Companion multiwav…